航海英语雷达及ARPA的使用章节练习(2018.02.03)

单项选择题
SWEEP INT on radar panel is the abbreviation of（）.
A.sweep introduction
B.sweep interest
C.sweep intention
D.sweep intensity
单项选择题
No assumptions（）on the basis of scanty information，especially scanty radar information.
A.should not be made
B.are not to be taken
C.should be taken
D.shall be made
单项选择题
When using the ARPA in heavy rain，which action should you take? （）
A.Increase the radar gain to pick up weak echoes through the rain
B.Increase the STC setting to reduce close-in spurious signals
C.Navigate as though the effective range of the radar has been reduced
D.Increase the range of the inner and outer guard rings
单项选择题
Your radar is set on a true motion display.Which of the following will NOT appear to move across the PPI scope（）.
A.Echoes from a buoy
B.Own ship's marker
C.Echo from a ship on the same course at the same speed
D.Echo from a ship on a reciprocal course at the same speed
单项选择题
It may be found that，in certain circumstances，radar beacon emissions can cause（）with the normal radar display，particularly at close range.
A.unwanted interference
B.unexpected figures
C.abnormal data
D.unwanted information
单项选择题
Which statement about an estimated position is TRUE?（）
A.It is more reliable than a fix based on radar bearings
B.It may be based on a single LOP or questionable data
C.When a 3-LOP fix plots in a triangle，the center of the triangle is the estimated position
D.It is usually based on soundings
单项选择题
The radar control used to reduce sea return at close ranges is the（）.
A.gain control
B.sensitivity time control
C.fast time constant
D.pulse length control
单项选择题
Radar reflectors are required for（）.
A.all fishing vessels over 39 feet in length
B.sail-propelled fishing vessels
C.all fishing vessels of less than 200 GT
D.wooden hull fishing vessels with a poor radar echo
单项选择题
Your ARPA has two guard zones.What is the purpose of the inner guard zone（）.
A.Alert the watch officer that a vessel is approaching the preset CPA limit
B.Warn of small targets that are initially detected closer than the outer guard zone
C.Guard against target loss during critical maneuvering situations
D.Sound an alarm for targets first detected within the zone
单项选择题
Which statement concerning the operation of radar in fog is TRUE?（）
A.Radar ranges are less accurate in fog
B.Navigation buoys will always show up on radar
C.A sandy beach will show up clearer on radar than a rocky cliff
D.Small wooden boats may not show up on radar